Purifying cast iron and eliminating objectionable gases and oxides



t J. R. BILLINGS. PURIFYING CAST IRON AND ELIMINATING OBJECTIONABLE GASES AND OXIDES. APPLI CATION FlLED MAY 25, 1916. RENEWED AUG. 25, 1921.

1,412,077. I Patented Apr. 11, 1922.

IIIIIIIIIII awn/1mm UNITED "STATES T-ENT- OFFEE.

JAMES R. BILLINGS, OF CHICAGO, ILLINOIS, ASSIGNOR TO J. B. IBILLINGS IRON & STEEL COMPANY, OF CHICAGO, ILLINOIS,.A CORPORATION OF SOUTH. DAKOTA.

PURIFYIN' G GAST IRON AND ELIMINATIN G OBJECTIONABLE GASES AN'D OXIDES.

Application filed May 25, 1916, Serial No. 99,879. Renewed August 25, 1921. Serial No. 495,280.

- citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Purifying Cast Iron and Eliminating Objectionable Gases and Oxides,'of which the following is a specification. v

My invention relates to the purification of crude pig iron, or iron having the characteristics of such crude pig metal, and has for its object to so treat the crude metal as to improve its qualities to such an extent that the improved metal will be suitable for making castings of all kinds; will be caholes; can. be worked by tools much more rapidly than the crude cast iron and will have greater strength than before treatment.

I have discovered that the character of the gases, whichiare always found in metallic crude iron, has a material effect on the physical and mechanical properties of the iron, and I have discovered that by removing,'as far as possible, the hydrogen and oxygen and any undesirable excess of phosphorus, and by dissolving as far as possible, the carbonic oxide, that a pig iron which has been obtained by the ordinary smelting method now in common use, i. e. by the use of a hot.

blast with coke as fuel,-can be transformed into an iron having, to a marked degree, the

desirable properties ofthe best qualities of charcoal pig iron, smelted in a blast furnace with a cold blast.' In other words, I have found that it is quite possible to produce from ordinary. pig iron, even of rather in ferior grade, by a simple and expeditious process, a hi h quality of pig iron corre.- spondin to t e high grade cold blast charcoal or wedish grades of pig iron.

The method of introducing the purifying agents which I employ is in general like that employed in my prior Patent No. 625,738, dated May 30, 1890; and the present invention may, to some extent, .be regarded as an addition to or improvement onthemethod described in that patent.

In carrying out my process I prefer-to (use an apparatus such as is disclosed in the accompanying drawings, althou h any other suitable apparatus may be emp oyed. 4

In the accompanying drawings, Fig. 1 is anaxial section view of a ladle and suitable ap ar'atus for introducing purifying materia Fig. 2 is a plan viewof the introducing meghanism pertaining to the ladle and shown in ig. 1' L Fig. is a perspective of a sheet metal cap.

1 designates a ladle, which may be of any usual and suitable type, 2 a platform constructed to extend above the ladle and proyided with an aperture 3 through which the introducing tube may be inserted, 4 the introducing tube as a whole, and 5 a supporting frame," conveniently taking the form of a box, through the lower end of which the introducing tube extends and to which it is pable of casting practically free from blow ri idly united, by screw threads as shown. he frame 5 is detachably held inplace on the platform by means of a set of hook-links tube 7 and an outer refractory covering 10 which covers so much of the tube as is liable to be inserted in the molten metal.

Withinthe tube 7 is arranged to reciprocate, an ejector plunger 18, the stem 19 of which is in the form of a rack which extends upwardly through the frame 5 and meshes with a spur-gear 20 mounted on a crank shaft'21, journaled to extend trans:

versely through the frame and conveniently operated manually by means of a crank .handle 22. A roller 23 journaled in a cross frame strip 5' just back of the rack 19 holds the latter in mesh with the gear. A tin or sheet iron cap 24 is provided, which is con- Specification of Letters Patent. Patented Apr, 11, 1 -922,

structed to fit tightly uponthe lower end of the'introducing tube and serves to hold the charge ofpurifyingmaterial'within the tube after it has'been placed therein.

.The process as carried out with the foreoing apparatus is substantially as foloWs:-A suitable batch of metal having been charged into the ladle, and the requisite amount of pulverulent material, such as hereinafter described, placed in the delivery end of the introducing tube, and confined therein, by placing the cap 24 upon the end of the tube, the latter is lowered through the platform into the metal and the frame made fast. As soon as the lower end of the tube is fairly within the molten metal the cap 24: will be melted off thus exposing the container material to the action of .the molten metal.

, To ensure the removal of the hydrogen, I introduce into the molten metal by means of the tube in the manner above described, a sufficient quantity of fiuorspar in a comminuted or finely divided state, from one to ten pounds of fluorspar per ton of molten pig iron being sulficient for this purpose, al.- though it is to be understood that I do not limit myself to any specific proportions.

In case the crude pig iron should contain more phosphorus than is regarded as desirable, the phosphorus content may readily be lowered by introducing into the molten metal, through the above mentioned mechanical device, a sufiicient quantity of preferably finely divided or comminuted sodium nitrate or other phosphorus-removing ingredients, one to ten pounds per ton of molten pig iron being used, although I do not wish to be limited to these specific proportions. Instead of nitrate of soda there may be used a mixture of calcium carbonate or oxide and fluorspar, and it is, therefore, quite possible to obtain the simultaneous removal of the hydrogen and any excess of phosphorus by properly proportioning the amount of added fluorspar.

. Finely divided carbon may also be intro-' duced, preferably after the other ingredients. The order in which the purifying agents are added may be attained by placing in the introducing tube, first, the carbon, then the phosphorus-removing agent, and thennearest the exit end, the hydrogen removing agent. All these operations can be so rapidly performed that the fluidity of the metal is not substantially lowered, and any loss ofheat in the treatment for the removal of hydrogen and phosphorus, oan be compensated by the additional heat furnished by the combustion of carbonaceous fuel. .The treatment above described has the added effect of practically freeing the molten metal from any oxide of iron and is also effective in eliminating the sulfur by chemical reaction due to the high temperature produced.

It is desirable tocast the meal when treated by the above process into cold molds, preferably made of iron, so that the metal as far as its content .of retained gases is concerned, will be maintained as far as possible in the condition'in which it is left by the treatment in the ladle. I

The product resulting from the treatment above described isan ironof superior quality with its objectionable gasesand. oxids eliminated, and which is peculiarly soft and tough and suitable for making castings which require machining or tooling. When.

remelted and used in foundry practice for making castings, this metal will cast sound and practically free from b'low holes, will tool much faster thancrude pig iron and is .much stronger thanbefore treatment. It is My method, therefore, enables the purification of crude pig iron either as it comes from the blast furnace or as obtainedby remelting mixtures of pig iron and scrap in the cupola, in such manner and with such results that it is adapted not only for making castings of all kinds, but is also a suitable base for high grade iron and steel manufacture.

I claim f 1. The improvement in the art of making iron which consists in introducing into the crude molten metal-a hydrogen eliminating agent, and a phosphorus-removing agent and then gradually and positively introducing into the body of the molten metal finely divided carbon.

2. The improvement in the art of making iron which consists in gradually and posi v 1 tively passing downwardly into the crude molten metal, a finely divided hydrogeneliminating agent, a phosphorus-removing agent, and finely. divided carbon.

In testimony whereof I afiix m' si ature.

' JAMES R. BI L GS. 

